1. Field of the Invention
The present invention relates to a powder conveyance device, a process unit using the powder conveyance device as a toner conveyance device, and an image forming device.
2. Description of the Related Art
In an image forming device, like a copier, a printer, a facsimile machine, or other multi-function peripherals (MFP), it is widely accepted to detachably attach a processing unit including processing means like image carriers, charging units, or toner containers to the image forming device, and as a result, it is possible to easily exchange the processing unit, and make maintenance easy.
In the related art, for example, Japanese Laid Open Patent Application No. 2-171791 (hereinafter, referred to as “reference 1”) discloses a processing unit able to recover residual toner on an image carrier, and supply the toner to a developing unit. The processing unit includes an image carrier, a charging unit, a developing unit, a cleaning unit, a toner container, a toner conveyance path, and a toner conveyance unit, and these elements are arranged in a housing of the processing unit. After image formation operations, toner remaining on the image carrier is removed by the cleaning unit, and the thus obtained toner is conveyed to the toner conveyance path by the toner conveyance unit. The end of the toner conveyance path extends to the toner container, and the toner conveyed by the toner conveyance unit is collected in the toner container. Then, the toner is supplied to the developing unit from the toner container.
In the processing unit disclosed in reference 1, however, the constituent components, that is, the image carrier, the charging unit, the developing unit, the cleaning unit, the toner container, the toner conveyance path, and the toner conveyance unit are integrally arranged in the one housing of the processing unit. Hence, for example, when the service lifetime of even one component is finished, other components still within their service lifetimes have to be exchanged or disposed of together.
To solve this problem, in recent years, a structure of the processing unit has been required in which the constituent components of the processing unit are respectively arranged in plural housings, the housings being detachably attached to each other, and the housings are then attached.
With such a structure, when the service lifetime of one component is over, this unit can be separated from other units for exchange or disposal.
When the processing unit is adopted which has plural housings, usually, it is necessary to provide plural toner conveyance paths in the processing unit corresponding to the housings, and when attaching the housings, a structure is required in which the plural toner conveyance paths can be easily and reliably attached and detached.